This invention relates generally to valves, and more specifically to a brine valve used in water softening systems.
A household water softener system typically includes a resin tank through which hard water passes to exchange its "hard" ions of calcium and magnesium for "soft" sodium ions. Regeneration of the resin bed is required periodically to replenish the supply of "soft" ions and to remove the accumulation of "hard" ions from the bed. The regeneration is effected by flushing a brine solution through the resin tank. A water softener of this type is more fully described in U.S. Pat. No. 3,891,552, issued June 24, 1975 to William C. Prior and James W. Kewley, entitled CONTROL VALVE FOR WATER SOFTENERS, the disclosure of which is incorporated herein by reference.
Modern water softeners of the type disclosed in U.S. Pat. No. 3,891,552 typically employ a brine tank which includes a reservoir and a supply of salt disposed at a level above the bottom of the reservoir. A tube connected to a source of water establishes a path for water to flow to the reservoir. Upon the attainment of a predetermined level in the reservoir, the water coacts with the salt supply to provide a source of brine for regeneration of the resin bed. When regeneration is required, the brine is aspirated through the same tube that supplied water to the reservoir. The amount of water introduced to the brine tank after a regeneration cycle and the amount of brine aspirated from the tank during a regeneration cycle is controlled by a brine valve mechanism.
One prior brine valve arrangement includes a float and a stem that extends downward from the center of the float into a valve housing through an apertured plate. The stem includes a rubber seal on each side of the plate. The rubber seals are adapted to abut either the upper, outer face of the plate or the lower, inner face of the plate to seal the plate apertures and close the valve mechanism. When brine is drawn from the tank through the apertures, the float lowers until the upper seal contacts the outer face of the plate to close the apertures and prevent any further outflow of brine. When fresh water is introduced into the brine tank, the float gradually rises until the lower seal closes the orifices.
This prior brine valve has two main disadvantages. One disadvantage is that the seals are easily fouled by dirt which can prevent the valve from closing. If this happens, the brine tank can overflow through the introduction of too much water causing possible damage to the surrounding area. The second main disadvantage is that the valve cannot be adjusted to change the amount of brine aspirated from the brine tank, while providing for a constant level of liquid when the tank is recharged with fresh water.
Another known brine valve is adjustable to vary the amount of brine drawn out of the brine tank of a water softener system commensurate with the rate of soft water use and the amount of brine needed to regenerate the resin bed. This conventional brine valve includes a stem extending upwardly from a valve housing and a float attached to the stem. The float and its associated stem are movable together in response to the level of brine in the tank to control the amount of liquid flow through the valve. The float can be slid along the stem to any selected position. By increasing the distance of the float from the housing, it is possible to increase the outflow of brine from the brine tank. The float position also controls the maximum level of water in the brine tank. The disadvantage is that the increased distance of the float from the housing results in more fresh water being introduced into the brine tank during replenishment of the supply of brine, so that more than a desired amount of the salt in the reservoir is submerged in water. The wet salt becomes mushy and tends to cake.
A need has existed for a brine valve capable of varying the amount of brine extracted from a brine tank of a water softener system without an attendant change in the highest level of brine in the reservoir. A need has also existed for a brine valve that is relatively free from malfunction and easy to assemble.